1. However, reinfection cannot be confirmed if clinical specimens from the initial coronavirus disease 2019 (COVID-19) illness are not available.Reinfection is known to occur with other human coronaviruses (HCoVs) 2.
A study in Kenya found that 4%–21% of people infected with endemic coronaviruses (HCoV-229E, NCoV-NL63, and HCoV-OC43) had two or more episodes of infection with the same virus species during a six-month period3.
Another study of HCoVs that used an antibody increase as a proxy for reinfection found that reinfections occurred at a median of 30 months but could occur as early as 6 months following the first infection4.